Apple Inc. has sold more than 1.2 billion iPhones since January 2007, when founder Steve Jobs triumphantly claimed, “Today, Apple is going to reinvent the phone.” That figure, based on quarterly results that include the 15 distinct models that came out before iPhones 8 and X, means that in terms of units sold, the iPhone is probably more successful than any consumer product ever created. The device has seeded entire industries—apps, most notably—and sent the stock prices of suppliers soaring. On the other hand, suppliers that have been spurned by Apple have struggled and, in at least one case, subsequently gone bankrupt.

The story of the device’s evolution is readily available to anyone willing to crack an old phone open and look at what’s inside. To understand this, we partnered with iFixit, the website known for publishing detailed “teardowns” of each phone, and IHS Markit, which produces estimates of the cost of electronics components.